Housing and stabilized mounting for underwater sound apparatus



Y, F. R. ELLENBERGER HOUSING AND STABILIZED MOUNTING March l, 1958 FOR UNDERWATER SOUND APPARATUS f\ 3 Sheets-Sheet 1 Filed Oct. l, 1945 F. R. ELLENBERGER Y HOUSING AND STABILIZED MOUNTING FOR March 11, 195s vUNDERWATER SOUND APPARATUS 3 Sheets-Sheet 2 Filed Oct. 1, 1945 Fig. 8.

ooonoo I'YwVenGQr: Franci s R El lenberger HOUSING AND STABILIZED MOUNTING FOR UNDERWATER SOUND APPARATUS March 11, 1958 F R. ELLENBERGE 2,826,749

Filed Oct. .1, 1945 5 Sheets-Sheet' 3 Irwvetof:

FYancis F2. El lerwloefgerw @Zw/mm' 771W I-ls Attofrw ey.

lira'ncsR,V Ellenb'erger, Schenectady, N. Y., assigner to General'Electric Company, a corporation of New York Application October 1,\194S,Seral1No. 619,642 s claims.` (Cl. 3A0-8)" invention frelates itoa fsoundlapparatus forf loc'ating-iobjectsaunder water and iparticulailyl tol thefmo'u'n'ting?` 'and stabilizing lof `fthe transducers ifor suchapparatus.

Apparatus employing :supersonic` wave energyunder water maybe arranged tofinvestigatean'area of the ocean -oor or aparticularrvolume around avessel `on in the name ori-Cramer'W;y La Pierre "et al. andassigned to the-same assigneeas the present invention. t This type of V equipment` employs L electroacoustic transducers for 11i-,fed States Paf 0f 2,326,749 een@ Me- 11 1958 2, Figa-Fis' a-fviewY of= aportionV of `the mounting-on the "opposite" side ofrthatshown-inFig: 1; Fig.' 7-isan enlarg'ed-secti'onal view of thebearing .and slip ringassembly forV the transducerlofFig.l 1;;F'g: 8 fis a' front elevation,

ice

5` "partlyfbrokeniaway, of the transducerk shown`in-Fig1 1;

Lind-'Figiy 9 vis a'fdiagranim'ati'c1viewnf'the stabilizing "control-of"thefapp'aratusofFig;` Vl.` g

Briefly, .the apparatus illustrated in the drawings 'comprises -fa waterproof housing of streamlined lor teardrop rltortn"-adaptedf-tobesupporteti from a vessel underwater with'itsf principal :axis'fini the ydilectitl'n of movement of the-fvesseL The'stabiliing`V motor dri-ves'lare' 'included Withinthe*- housing` andf the"y control 1 cables `may be con- -nectedthrough" a suitable' duetto equipment von the --vesse1r- A111electroacoustictransducer is-mounted 'ona bracketfextending-sfrom afdrum or barrel which is stabilizetl'topreventchanges in position of the-transducer due'ltorollingiof the'l'vess'el-.l The' transducer is 'also'stabilizedtaboutan `axis' `=at"1"ight= angles to `the roll axis to correct-'tor niovementsfdueto 'pitchingof the vessel. The which the apparatus is mounted; An apparatustr-this #purpose fis Adescribed i and Aclaimed `in Ia lcopending' applii -cation Seria-LNG; 619,720 filed concurrently herewith `transduberiisrotatedfabout -a'vertical axis duringV opertation' inlorderft scan apredeterminedvolume of Water 'in thneighborhoodliof the'vessel.A The-control motors and othefmoving p'a'rts'tof tliecontrolV located withinthe transmitting the sound energyy and for'receiving echoes j' from objects in the Y eld under investigation.` Because ,relatively? narrow', `highly directive beamsare ut'ilized, these transducers Smust be -stabilized fsolthat ytheylarelnot subject to angular motion because of `the rolling :and

pitching-of-thefves`sel on which the apparatus is fmou'nted.

Furthermore-lit is desirable to arrange "thetransdu'cers' within.` closed housings having" minimum resistance` t'o rnovementrof the water inthe direction of movement ofV thevessel. Certain controlequipment, fsuchfas the 1 Refterringnow to the drawingsgthe "apparatus illustrated in Fig. l comprisesthef'dtum"lfcomprising" a hollow Yshattfl h'avirigla reducedjdiamet'ersolid eirtens'inportion' 12f-secured toithedrum in' alineme'nt"'therewith 'and Umounted 'in-fa' roller l bearing 13 `in anupiight lblaclet" '14 drivingmotors-for stabilizing `the transducer, must -be' I located in `the fluid-tight housing and it is desirable thatl water or other liquid surroundingfthe working-.parts be positively prevented from entering the casingtorother containers in which they are'mounted. Accordingly,

itjis an object of this invention to provide an equipment` j for transmitting or receiving sound under water includingaan improved arrangement for mounting the-control motors and other lapparatus for actuatingthe equipment.

mounting y for electroacoustic transducers or the like'rfor operation under water includingan improved ari-angementv forVV maintaining Vthe transducers stabilized in a desired position regardless of rolling of the vessel-to which the equipment is attached.`

It is Vanotherobject Vof `this -invention toprovideza mounting `iorelectroacoustic transducers or the like 'for operation under water including' an improved l `arrangement for maintaining the transducers stabilized #regardless of rolling of the vessel and for rotating endpointing the transducers `in desired directions to determine the zone of operation of said transducers.

The lnovel features which are believed to becharacteristic of this invention are set forth withvparticularity both'as toits organizationand method of operation, together with further` objects and advantages thereof, may best be understood by ,reference to the followingidescription ltalk'en'inconnection with the accompanyingrdrawings"`in"whicli"Fig." 1 `is' `a "sectional side elevation of uan underwater housing lfor an "electroacoustic"transducer including A'a' mounting embodying the invention;` Figs. 2,' 3 'andl4'are diagrammatic end views of the housing 'shown inl-Fig. 1 illustratiiigithreeangular positinsthereofilduring rolling-'ofi the ivessel; IFigf-S -is fa plan viewypartlyin section; of f the :transducer -finountingshown iin f Fi-gE f1;

ing113v and 1a sheet metal shelllorhousin'gfljis ysecured It Ais another object ofthe invention to-provide a o f-is I provided withinfthe'disk 16" outside the bearing as- -the'drfm through theihollow boss 17. Theseele'ctric in :the appende'daclaims. The Yinvention itself, however,

-9 1at"the1lhighestpoint infthe housing' anelectric motor 28 'Sis`5ni'ount`ed on agear boir29'rigidly secured to the supporting plate 15 and 'arranged to drive a vpinionf30`to move the'drum about Ya' gear 31 rigidly secured to the boss17. The Vmotor 28is controlled in accordance with "lateri 'sof-that:itoperatesftc 'maintain tliedrrn 10in a predetermined hx'ed position' regardless of rolling vofthe vessel. As indicated in Figs. 2, 3 and 4, the transducer assembly 8 is maintained upright because it is secured to the stabilized drum regardless of the position of the housing 1 as it is shifted during rolling of the vessel. In Fig. 2 the vessel has rolled to starboard, in Fig. 3 it is upright, and in Fig. 4 the vessel has rolled to port. In each of these figures a supporting arm between the vessel and the housing 1 has been indicated at 32 and this arm remains xed with respect to the vessel.

The space within the housing surrounding the drum 10 and the transducer assembly 8 is filled with a suitable liquid, such as a water solution of sodium chromate, which has sound transmitting characteristics similar to those of water but which does not tend to corrode the equipment within the housing. The housing thus provides a streamlined casing for minimizing the resistance of the apparatus'to its passage through water during movement of the vessel and insures operation of the trans- Yducer assembly in a body of liquid not disturbed by movement of the vessel. The arrangement also prevents corrosion of the apparatus within the housing which would be caused if it were immersed, for example, in sea water. The sodium chromate solution is admitted to the casing through a connection 33 arranged in the bracket 27 so that the solution may be carried to the housing through the supporting arm 32. When it is desired to drain the chromate solution back into its container aboard the vessel, the housing is arranged to be inverted and a plug 34 may be removed from the side opposite the connection 33 in order to admit air to the interior of the housing and facilitate drainage of the solution back through the connection 33. A vent tube and plug, as indicated at 33a and 33b, respectively, permit tilling the hose completely as a portion of it is above level of plug 34 when inverted.

In order to stabilize the transducer assembly 8 against movement due to pitching of the vessel, the assembly is mounted for rotation about the axis of a shaft 35 in the head 36 of the transducer. This mounting arrangement for stabilizing the transducer against pitching of the ship and including the pendulous mounting of the transducer is described and claimed in a copending application Serial No. 619,643 led concurrently herewith in the name of George W. Kessler and assigned to the same assignee as the present invention. The transducer assembly is thus mounted for pendulous motion about the end of the bracket 9 and the pitch correction thus provided in cooperation with the movement of the barrel 10 with respect to the housing to correct for roll insures the maintaining of the transducer 8 in a stable position regardless of rolling and pitching of the vessel. During operation the transducer assembly 8 is also rotated about a vertical axis passing through the head 36. The motors for driving the transducer assembly to correct for pitch and to provide the rotation thereof are mountedwithin the drum 10, the pitch correctionmotor being indicated at 37 and the rotation motor at 38. The motor 37 drives a gear segment 39 on the shaft 35 through a reduction gearing 40, a pair of pinion gears 41, a shaft 42, and a bevel pinion 43 engaging the sector 39. The motor 38 drives a gear 44 through a reduction gearing 45, pinions 46, shaft 47, and a bevel pinion 48. The connections between the reduction gearings within the drum 10 and the pinions 41 and 46 rotate in fluid-tight seals (not shown) and mounted in the plate 20. When the motor 38 drives the gear 44, the transducer is rotated about its vertical axis through a bevel gear 49 secured to an extended hub 50 on the gear 44 and which engages a similar bevel gear 51 secured to a rotatable sleeve 52 mounted within the head 36 on a bearing assembly 53. The transducer assembly 8 includes a transducer unit 54 suspended from the head 36 on arms 55 providing a downwardly opening U-shaped bracket secured to the sleeve 52, the lower portion of which is an integral block or base 56 of rectangular cross section.

' ,as the present invention.

linterior of the casing 62 and the unit may be rotated with The transducer unit 54 thus may swing pendulously within the bracket 9 on ball bearing assemblies 57 and 58 mounted within the left-. and right-hand brackets as viewed in Fig. 7, the bearing assembly 57 being mounted directly on the head 36 and the bearing 58 on the hub 50 of the gear 44 which inturn is mounted in ball bearing assemblies 59 on the shaft 35. The transducer 54 may also be rotated about an upright axis within the head 36 by operation of the gears 44, 49 and 51.

The transducer unit 54 comprises two transmitting transducers 66 and 61 mounted back to back on a casing er housing 62 which is constructed to provide a huid-tight chamber between the two transducers.V T wo transducers are employed in order that either of two selected frequencies may be utilized, it being desirable under some conditions to operate at a lower frequency in order to increase the range of the equipment and under other conditions to operate at a higher frequency in'order to increase the accuracy of the equipment. The transducers y 60 and 61 are of a type designed to transmit a relatively wide beam of supersonic energy and during the operation of the apparatus it is desirable to vary the declination of the beam in order to investigate objects in the water at different angles. For examples, at one time an object under investigation may be directly forward of the Vessel and at Vanother time it may be desirable to examine the ocean floor. In order to change the declination of the transducer unit 54, it is secured between the arms 55 on stub shafts 63 rigidly mounted in blocks 64 at the lower ends of the arms. The structural features of the transducer 61 are similar to the transducer described and claimed in copending application Serial No. 619,722, filed concurrently herewith in the names of William H. Janssen and Richard W. Samsel and assigned tothe same assignee The stub shafts extend to the respect to the arms 55 by operation of a selsyn motor 65 secured in the housing 62 on a bracket 66 and arranged to drive a worm 67 and rotate the housing about a stationary gear 63 through a reduction gearing 69. The limits of declination about the shafts 63 are determined by adjustable stops '70 and 71 secured on the outside of the transducer housings 60 and 61, respectively, and arranged to engage the adjacent block 64 at the maximum .permissible positions in the two directions of rotation about the shaft 63.

' In order to carry the electrical connections to the motor 65 and to the transducers 60 and 61, sealed conduits are provided, a hollow connection 72 being provided between the interior of the casing 10 and a connection or terminal box 73 which is provided with a removable cover so that during servicing of the apparatus, connections may be broken between the interior of the casing 10 and the transducer assembly 8. The electrical leads (not shown) are carried to the transducer head 36 from the box 73 through a flexible conduit 74 and reach the interior of the head 36 which is provided with a downwardly extending post 75 of insulating material and in which a plurality of brushes 76 are mounted. Encircling the post 75 and rigidly mounted in the sleeve 52 is an insulating sleeve 77 provided 4with a plurality of spaced slip rings 78 each arranged to engage one of the brushes 76. The leads from the slip rings, two of which are indicated at '79, pass longitudinally through the sleeve 77 and into passages 80 and 81'in the block 56. It is thus apparent that the sleeve 52 may rotate Within the head 36 without interruption of electrical connections. The high frequency connections to the transducers may, if desired, be made throughan inductive coupling, generally indicated by a primary member 82secured to the lower end of the post 75 and a secondary member 83 secured in ay plate 84V at the lowerrend of the insulating sleeve 77 within the block 56. The connections to the transducer 60 are Kmade through a texible conduit 85 connecting the-pas sage S and theinteriorj of theJIansducer 60, -and the leadsto the transducer 61 are carried through' a-flxib'le conduit 86connecting the passageiland xthe'interior of the'transducer 61; The leads .for controliingsthe .selsyn motor 65 withinthe: housing62 are carriedirom .a passage (not shown) inthe blockA 56`andv thence through aconnection 87 and "a exible conduit 88 vto .the interior ofthe housing 62.* All of the passages and iexiblconduitsbetween the casing 'and 'the transducers 60"and 61'andthecasing'62 are made 'uid tight. All these spaces .are arranged to beiilled with a suitable gas, such asdry airv or`nitrogen, whichv is maintained under sutilcient pressure to` prevent the leakage of the sodium chromate orother solution into the control chambers of the-apparatus. In .order to'seal the space withinthe head 36between the stationaryl parts .of the head and the rotating sleevef52, ashaft'seal 89 similar to the. seal 22"at therear end ofithe casing10 is provided. This sealincludes an annular flexible lrubbershoulder1'90 which engages Ythe rotating :sleeve 52 .and is `arranged iso that. the

pressure of .the gaswithin the head increases the eectiveness'of the seal.v The gas under pressuremayfbe admitted from asuitable supply'in the vessel through" the connection 26 and the hollow boss 17 to.the.casing 10 and `thence -to the several conduits of .the transducer as sembly. It will thus be apparent that la stabilizing'equipment has beenprovided which'makes Vit possible to maintain. an electroacoustic `transducerin a desired stable position under water withiminimum likelihood of damage to the stabilizing equipment due to leakage of water or otherliquid into.the controlV chambers. 4

The mechanism forI controlling the apparatus shownin Fig., 1in order to maintain .the transducenassemblystabilized in a vdesired positionis showndiagrammatic'ally in Fig..9 where the drum 10"has 'been'iridicated 'byat dotted outline, .parts o'f the apparatus within' the .drum being shown within the outline. The powerY supply circuits have Abeen omitted from thev drawingjto avoid unnecessary complication, the mannerof applying power to control circuits of the .type indicated being wellknown a in the.art. The stabilizing,equipmentincludesa'gyroscope 91 arranged in accordance withl well-known. practice in a .Cardan mountingwvhichV includes'gimbal rings 92 and '93 lwhich rotate .about axes 94 and v95,` respectively, in accordance with the roll and pitch'of the vessel, the gyroscope rotor indicated at,96.rotating continuously about a vertical axisthroughourthe operation of the equipment. Whenzthe vessel rolls .the :rotation of ring 92 about its axis 94 drives a selsyn 97 Aand. transmits .asignal tof a selsyn 9S "which'is" geared directly -in a 1:1 ',.ratioQto thedrum 10. The selsyn 98"thereupon.transmits. asignal to-.a servo amplifier equipment 99 which drives .themotor 28 `to rotate the drum 10`until 'the selsyn 98 Vis" in the same position as the selsyn 97. The operation of the selsyns 97 and 98 is such that the motor 28 is driven substantially simultaneously with the rolling of the vessel, as indicated by the gyroscope, and the drum 10 is maintained stable regardless of the rolling of the vessel. In a similar manner the transducer assembly 8 is moved pendulously about the axis of the shaft in accordance with pitch, this latter control being effected through a selsyn 100 driven by the gimbal ring 93 and arranged to control the motor 37 through a followup selsyn 101 and a servo amplifier equipment 102. The rotation of the transducer unit 54 is controlled by a driving motor 103 which drives a selsyn 104 and thereby controls the rotation of the motor 38 through a followup selsyn 105 and a servo amplifying equipment 106, the selsyn 105 being geared directly to the shaft 47 which drives the transducer. As explained in the aforementioned Kessler application, it is necessary to correct the rotation of the transducer for the pitching movement of the vessel, and the selsyn 104 is therefore constructed as a differential selsyn and a signal from the pitch selsyn 101 is supplied to the selsyn 104 through a cable 107. This control arrangevwitha. particular type of'supersonic equipment, other ment prevents change in the rate of rotation. of-.the trans- ,ducer'which'would otherwsebe causediby the pendlous movement of lthe `transducer.l about'the driving, gear 49.

The'operati'on of the 'selsynmotor 65'within the hous-V ing 62. is controlled`b`y.a drivingmotor. 108"`connected through' a gearing'109 to a selsyn 110 which is coupled to the selsyn 65. The power required for this drive' is sutil- .ciently small and that it is not necessary to employ aservo rangement of .the drum 10`forsupportingthe-'transducer assembly andfor maintaining the assembly stabilized against rolling of :the vessel'provides a"sirnple constructi'onl for eiectively; sealinga1l"parts` ofthe equipment against leakage .of water andother liquid into the working parts'andf furthermore facilitates the mounting` of the transducer for pendulous movement. Control ofall'th'e required'stabilizingmovements and direction adjusting movements maythus be electe'd from a remote position.

While the invention has been described in connection applications wi11`readilybe apparent -tothose skilled 'in the art. It is '.not, therefore, ldesired lthat the invention be limited to. the specilic construction .described and illlstrated,` and it. is in'tende'dbyA the 4appended-claims to cover alll modifications within the spirit and'scope of theirivention.

`What'I`claim as new and 'desire -to secure-byillettrs Patent of theUiiitedS'tates-is: `1.` A11-.apparatus for mountingand stabilizing an electroacous'tic transducer-under water on afvessel subject topitching and rolli'ng comprising a substantially watertight. casing ,arranged to be mounted" on the vesselfo'r rotation-.about'an axis parallel 'tothe axis of rollA ofthe 40 .vesselpa device to be stabilized arranged to be supported onsa'idfcasing about an axis parallel to the pitch 'axis lof the Vessel, and means including rmotors arranged "Within said casing, for moving lsaid "casing, and `said-device-about their respective axeswhereby said device may be maintained in a'predetermined position regardless of the pitchirig and rollingof the vessel.'

2." Anapparatus for mountingand stabilizing van yelectroacoustic transducer under waterson a vessel subject `t o pitchingand rolling comprising a substantially watertight casing arranged to be mounted 'on Vthe vesselfor rotation about'an axis parallel to the axis of roll of "the vessel,V means in said casinggfor rotating, said Lcasing',v a device to bestabilized arranged .to be supported on said casing `aboutan axis parallel t the pitch"axis'of"the vessel, and means for admitting gas under pressure to said casing to minimize the likelihood of leakage of uid into the casing.

3. An apparatus for mounting and stabilizing an electroacoustic transducer under Water on a vessel subject to pitching and rolling comprising a closed housing arranged to be mounted on the vessel and to be positioned under water, said housing having a sound transmitting window therein, a substantially water-tight casing mounted in said housing for rotation about an axis parallel to the axis of roll of the vessel, an electroacoustic transducer supported on said casing near said window and on an axis parallel to the pitch axis of the vessel, means including motors arranged within said casing for moving said casing and said transducer about their respective axes whereby said transducer may be maintained in a position for the transfer of sound energy in a predetermined direction regardless of the pitching and rolling of the vessel, and a body of liquid having sound transmitting characteristics similar to water illing said housing about said transducer and said casing.

4. A11 apparatus for mounting and stabilizing an electroacoustic transducer under therein, a substantially water-tight casing mounted in said housing for rotation about an axis parallel to the axis of roll of the vessel, an electroacoustic transducer supported on said casing near said window and onan axis' parallel to the pitch axis of the vessel, means including motors arranged within said casing for moving said casing and said transducer about their respective axes whereby said transducer may be maintained in a' position for transferring sound energy in a predetermined direction regardless of the pitching and rolling Vof the vessel, a body of liquid having sound transmitting lcharacteristics similar to water filling said housing about said transducer and said casing, means for admitting gas underV pressure to the interior of said casing to minimize the likelihood of leakage of the surrounding fluid into the casing, and means arranged for carrying electrical conductors into said casing for controlling said apparatus from a remote position.

5. An apparatus for mounting and stabilizing an electronacoustic transducer under wa'ter on a vessel subject to pitching and rolling comprising a closed housing arranged to be mounted on the vessel and to be positioned under water, said housing comprising a rigid shell portion and a dome-shaped portion of material having sound transmitting characteristics similar to water and secured on said shell, a substantially water-tight casing mountedl in said shell portion for rotation about an axis parallel to the axis of roll of the vessel, a bracket on said casing extending into said dome portion, an electroacoustic transducer supported on said bracket within said dome portion and on an axis parallel to the pitch axis of the vessel, s

means including motors arranged within said casing for moving said casing and said transducer about their respective axes whereby said transducer may be maintained in a predetermined position regardless of the pitching and rolling of the vessel, means including a motor within said casing for rotating said transducer about its vertical axis, and a body of liquid having sound transmitting characteristics similar to those of water filling said housing about said transducer and said casing.

6. An apparatus for mounting and stabilizing an electroacoustic transducer under water on a vessel subject to pitching and rolling comprising a substantially watertight casing arranged'to be mounted on thevessel for rotation about an axis parallel to the axis of roll oi the vessel, an arm on said casing extending axially therefrom, a supporting assembly having a transducer thereon and arranged to be supported on said arm for pendulous movement about an axis parallel to the axis of pitch of the vessel, means including seems a motor within said casing for moyinglsaid` assembly about its-supporting axis whereby Vsaid,` assemblyinlay be-maintained in-a predetermined kposition regardless 4of the pitching andfrolling of the vessel, means providing a water-tight compartment on said assembly, and means including a motor mounted within said compartment for adjusting the declination of said transducer to determine the direction of transfer of soundenergy between said transducer and the surround- 7. An apparatus for mounting an electroacoustic translducergunder water comprising a substantially water-tight casing, an armextending from said casing, a bearing vmeans including a motor within said casing for rotating `said assembly, conduit means for carrying electric leads to said transducer assembly, a slip ring assembly arranged within said bearing assembly, means including a housing for said bearing assembly for enclosing said assembly in a Huid-tight chamber, and means for supplying gas under pressure to said casing and through said conduit to said bearing chamber for preventing leakage of liquid into said casing and chamber.

8. An apparatus for mounting an electroacoustic transducer under water comprising a substantially water-tight casing, an arm extending from said casing, a transducer, a hanger for said transducer, a supporting head for said hanger rotatably mounted on said arm remote from said casing, means including a bearing within said head for aording rotation of said hanger about an axis transverse to the axis of rotation of said head on said arm, housing means for supporting said transducer and providing a D fluid-tight chamber, electric driving means in saidchamber for adjusting the angular position of said transducer with respect to said hanger, and means'i'ncluding a slip ring assembly in said head for carrying electric leads from said casing to said transducer chamber and for providing a Huid-tight enclosure for the leads between said casing and said transducer chamber whereby said casing and said housing and said chamber and said lead enclosure may be filled with a gas under pressure to minimize leakage of liquid into said apparatus.

References Cited in the le of this patent UNITED STATES PATENTS 

